Fix a few minor "extra" compiler warnings (mostly "const" issues)

Add "XXX" comments in a few places about potential problems seen in SCST code,
for future investigation and possible repair.

Signed-off-by: David Butterfield <dab21774@gmail.com>



git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7123 d57e44dd-8a1f-0410-8b47-8ef2f437770f

iscsi-scst/kernel/iscsi.c

@@ -509,6 +509,11 @@ void cmnd_done(struct iscsi_cmnd *cmnd)
 			if (cmnd->sg != &dummy_sg)
 				scst_free_sg(cmnd->sg, cmnd->sg_cnt);
 #ifdef CONFIG_SCST_DEBUG
+			/*
+			 * We can make correct behavior depend on this, so
+			 * a bug can disappear whenever you enable debugging,
+			 * but probability of failure on zero/NULL is much bigger
+			 */
 			cmnd->own_sg = 0;
 			cmnd->sg = NULL;
 			cmnd->sg_cnt = -1;
@@ -2911,7 +2916,7 @@ out:
 	return;
 }
 
-static void set_cork(struct socket *sock, int on)
+static inline void set_cork(struct socket *sock, int on)
 {
 	int opt = on;
 	mm_segment_t oldfs;

iscsi-scst/kernel/nthread.c

@@ -1687,7 +1687,7 @@ static int tx_padding(struct iscsi_cmnd *cmnd, int state)
 	int res, rest = cmnd->conn->write_size;
 	struct msghdr msg = {.msg_flags = MSG_NOSIGNAL | MSG_DONTWAIT};
 	struct kvec iov;
-	static uint32_t padding;
+	static const uint32_t padding;
 
 	BUG_ON(rest < 1);
 	BUG_ON(rest >= sizeof(uint32_t));

iscsi-scst/usr/chap.c

@@ -105,6 +105,9 @@ static u8 decode_base64_digit(char base64)
 		else if ((base64 >= '0') && (base64 <= '9'))
 			return 52 + (base64 - '0');
 		else
+			//XXX This return value should be unsigned; and anyway
+			//XXX in case of a bad character in the string, our
+			//XXX caller (sometimes) checks for 65, not 255 or -1
 			return -1;
 	}
 }
@@ -146,6 +149,8 @@ static void decode_base64_string(char *string, u8 *intnum, int int_len)
 	num[1] = decode_base64_digit(string[count + 1]);
 	num[2] = decode_base64_digit(string[count + 2]);
 	num[3] = decode_base64_digit(string[count + 3]);
+	//XXX Check for the special "bad character in string" value here like above?
+	//XXX Also check the string for missing/incorrect padding?
 	if ((num[0] == 64) || (num[1] == 64))
 		return;
 	if (num[2] == 64) {

iscsi-scst/usr/config.c

@@ -1144,7 +1144,7 @@ int config_load(const char *config_name)
 
 	err = config_isns_load(buf);
 	if ((err == 0) && (isns_server != NULL)) {
-		int rc = isns_init();
+		rc = isns_init();
 
 		if (rc != 0) {
 			log_error("iSNS server %s init failed: %d", isns_server, rc);

scst/include/scst.h

@@ -4081,8 +4081,8 @@ static inline enum scst_exec_context __scst_estimate_context(bool atomic)
 	else if (in_atomic())
 		return SCST_CONTEXT_DIRECT_ATOMIC;
 	else
-		return atomic ? SCST_CONTEXT_DIRECT :
-				SCST_CONTEXT_DIRECT_ATOMIC;
+		return atomic ? SCST_CONTEXT_DIRECT_ATOMIC :
+				SCST_CONTEXT_DIRECT;
 #else
 	return SCST_CONTEXT_THREAD;
 #endif

scst/src/dev_handlers/scst_vdisk.c

@@ -83,7 +83,7 @@ static struct scst_trace_log vdisk_local_trace_tbl[] = {
 #define SCST_FIO_VENDOR			"SCST_FIO"
 #define SCST_BIO_VENDOR			"SCST_BIO"
 /* 4 byte ASCII Product Revision Level - left aligned */
-#define SCST_FIO_REV			" 330"
+#define SCST_FIO_REV			"330 "
 
 #define MAX_USN_LEN			(20+1) /* For '\0' */
 #define MAX_INQ_VEND_SPECIFIC_LEN	(INQ_BUF_SZ - 96)
@@ -2081,8 +2081,11 @@ static int vdisk_format_dif(struct scst_cmd *cmd, uint64_t start_lba,
 			goto out_set_fs;
 		} else if (err < full_len) {
 			/*
-			 * Probably that's wrong, but sometimes write() returns
-			 * value less, than requested. Let's restart.
+			 * If a write() is interrupted by a signal handler before
+			 * any bytes are written, then the call fails with the
+			 * error EINTR; if it is interrupted after at least one
+			 * byte has been written, the call succeeds, and returns
+			 * the number of bytes written  --  manpage write(2)
 			 */
 			left += full_len - err;
 			done -= full_len - err;

scst/src/scst_lib.c

@@ -11695,15 +11695,15 @@ uint64_t scst_unpack_lun(const uint8_t *lun, int len)
 	case 2:
 		break;
 	case 8:
-		if ((*((__be64 *)lun) & cpu_to_be64(0x0000FFFFFFFFFFFFLL)) != 0)
+		if ((*((__be64 const *)lun) & cpu_to_be64(0x0000FFFFFFFFFFFFLL)) != 0)
 			goto out_err;
 		break;
 	case 4:
-		if (*((__be16 *)&lun[2]) != 0)
+		if (*((__be16 const *)&lun[2]) != 0)
 			goto out_err;
 		break;
 	case 6:
-		if (*((__be32 *)&lun[2]) != 0)
+		if (*((__be32 const *)&lun[2]) != 0)
 			goto out_err;
 		break;
 	case 1:
@@ -13870,10 +13870,10 @@ EXPORT_SYMBOL(scst_reassign_retained_sess_states);
 char *scst_get_next_lexem(char **token_str)
 {
 	char *p, *q;
-	static const char blank = '\0';
+	static char blank = '\0';
 
 	if ((token_str == NULL) || (*token_str == NULL))
-		return (char *)␣
+		return ␣
 
 	for (p = *token_str; (*p != '\0') && (isspace(*p) || (*p == '=')); p++)
 		;
@@ -14874,7 +14874,7 @@ int scst_write_file_transactional(const char *name, const char *name1,
 
 	pos = signature_len+1;
 
-	res = vfs_write(file, (void __force __user *)buf, size, &pos);
+	res = vfs_write(file, (void const __force __user *)buf, size, &pos);
 	if (res != size)
 		goto write_error;
 
@@ -14885,7 +14885,7 @@ int scst_write_file_transactional(const char *name, const char *name1,
 	}
 
 	pos = 0;
-	res = vfs_write(file, (void __force __user *)signature, signature_len, &pos);
+	res = vfs_write(file, (void const __force __user *)signature, signature_len, &pos);
 	if (res != signature_len)
 		goto write_error;
 

scst/src/scst_targ.c

@@ -1552,9 +1552,13 @@ static int scst_prepare_space(struct scst_cmd *cmd)
 			goto alloc;
 		else if (r == 0) {
 			if (unlikely(cmd->bufflen == 0)) {
-				/* See comment in scst_alloc_space() */
-				if (cmd->sg == NULL)
+				if (cmd->sg == NULL) {
+					/*
+					 * Let's still have a buffer for uniformity,
+					 * scst_alloc_space() will handle bufflen 0
+					 */
 					goto alloc;
+				}
 			}
 
 			cmd->tgt_i_data_buf_alloced = 1;

usr/fileio/common.h

@@ -30,7 +30,7 @@
 /* 8 byte ASCII Vendor */
 #define VENDOR				"SCST_USR"
 /* 4 byte ASCII Product Revision Level - left aligned */
-#define FIO_REV				" 330"
+#define FIO_REV				"330 "
 
 #define MAX_USN_LEN			(20+1) /* For '\0' */